--- ray/src/util/rmatrix.c	2023/12/04 22:02:40	2.69
+++ ray/src/util/rmatrix.c	2023/12/06 17:57:34	2.73
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rmatrix.c,v 2.69 2023/12/04 22:02:40 greg Exp $";
+static const char RCSid[] = "$Id: rmatrix.c,v 2.73 2023/12/06 17:57:34 greg Exp $";
 #endif
 /*
  * General matrix operations.
@@ -374,14 +374,15 @@ rmx_load(const char *inspec, RMPref rmp)
 		fp = stdin;
 	else if (inspec[0] == '!')
 		fp = popen(inspec+1, "r");
-	else if (rmp != RMPnone) {
+	else {
 		const char	*sp = inspec;	/* check suffix */
 		while (*sp)
 			++sp;
 		while (sp > inspec && sp[-1] != '.')
 			--sp;
 		if (!strcasecmp(sp, "XML")) {	/* assume it's a BSDF */
-			CMATRIX	*cm = rmp==RMPtrans ? cm_loadBTDF(inspec) :
+			CMATRIX	*cm = rmp==RMPnone ? (CMATRIX *)NULL :
+					rmp==RMPtrans ? cm_loadBTDF(inspec) :
 					cm_loadBRDF(inspec, rmp==RMPreflB) ;
 			if (!cm)
 				return(NULL);
@@ -449,7 +450,7 @@ rmx_write_ascii(const double *dp, int nc, int len, FIL
 {
 	while (len-- > 0) {
 		int	k = nc;
-		while (nc-- > 0)
+		while (k-- > 0)
 			fprintf(fp, " %.7e", *dp++);
 		fputc('\t', fp);
 	}
@@ -527,7 +528,7 @@ findCIEprims(const char *info)
 int
 rmx_write_header(const RMATRIX *rm, int dtype, FILE *fp)
 {
-	if (!rm | !fp || !rm->mtx | (rm->ncols <= 0))
+	if (!rm | !fp || rm->ncols <= 0)
 		return(0);
 	if (rm->info)
 		fputs(rm->info, fp);
@@ -665,6 +666,30 @@ rmx_copy(const RMATRIX *rm)
 	copycolor(dnew->cexp, rm->cexp);
 	memcpy(dnew->wlpart, rm->wlpart, sizeof(dnew->wlpart));
 	return(dnew);
+}
+
+/* Replace data in first matrix with data from second */
+int
+rmx_transfer_data(RMATRIX *rdst, RMATRIX *rsrc, int dometa)
+{
+	if (!rdst | !rsrc || (rdst->nrows != rsrc->nrows) |
+			(rdst->ncols != rsrc->ncols) |
+			(rdst->ncomp != rsrc->ncomp))
+		return(0);
+
+	if (dometa) {		/* transfer everything? */
+		rmx_reset(rdst);
+		*rdst = *rsrc;
+		rsrc->info = NULL; rsrc->mapped = NULL; rsrc->mtx = NULL;
+		return(1);
+	}
+	if (rdst->mapped)
+		return(0);	/* XXX can't handle this case */
+				/* just matrix data -- leave metadata */
+	if (rdst->mtx) free(rdst->mtx);
+	rdst->mtx = rsrc->mtx;
+	rsrc->mtx = NULL;
+	return(1);
 }
 
 /* Allocate and assign transposed matrix */